Commit 4c5a8442 authored by Michael S. Tsirkin's avatar Michael S. Tsirkin Committed by David S. Miller
Browse files

vhost: cleanup iterator update logic 



Recent iterator-related changes in vhost made it
harder to follow the logic fixing up the header.
In fact, the fixup always happens at the same
offset: sizeof(virtio_net_hdr): sometimes the
fixup iterator is updated by copy_to_iter,
sometimes-by iov_iter_advance.

Rearrange code to make this obvious.

Signed-off-by: default avatarMichael S. Tsirkin <mst@redhat.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 5f2ebfbe

drivers/vhost/net.c

+12 −10
Original line number Diff line number Diff line
@@ -591,11 +591,6 @@ static void handle_rx(struct vhost_net *net) 
			 * TODO: support TSO.

			 */

			iov_iter_advance(&msg.msg_iter, vhost_hlen);

		} else {

			/* It'll come from socket; we'll need to patch

			 * ->num_buffers over if VIRTIO_NET_F_MRG_RXBUF

			 */

			iov_iter_advance(&fixup, sizeof(hdr));

		}

		err = sock->ops->recvmsg(NULL, sock, &msg,

					 sock_len, MSG_DONTWAIT | MSG_TRUNC);
@@ -609,12 +604,19 @@ static void handle_rx(struct vhost_net *net) 
			continue;

		}

		/* Supply virtio_net_hdr if VHOST_NET_F_VIRTIO_NET_HDR */

		if (unlikely(vhost_hlen) &&

		    copy_to_iter(&hdr, sizeof(hdr), &fixup) != sizeof(hdr)) {

			vq_err(vq, "Unable to write vnet_hdr at addr %p\n",

			       vq->iov->iov_base);

		if (unlikely(vhost_hlen)) {

			if (copy_to_iter(&hdr, sizeof(hdr),

					 &fixup) != sizeof(hdr)) {

				vq_err(vq, "Unable to write vnet_hdr "

				       "at addr %p\n", vq->iov->iov_base);

				break;

			}

		} else {

			/* Header came from socket; we'll need to patch

			 * ->num_buffers over if VIRTIO_NET_F_MRG_RXBUF

			 */

			iov_iter_advance(&fixup, sizeof(hdr));

		}

		/* TODO: Should check and handle checksum. */



		num_buffers = cpu_to_vhost16(vq, headcount);

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